The Prevalence and Risk Factors for Pneumococcal Colonization of the Nasopharynx among Children in Kilifi District, Kenya

BACKGROUND: Pneumococcal conjugate vaccines (PCV) reduce nasopharyngeal carriage of vaccine-serotype pneumococci but increase in the carriage of non-vaccine serotypes. We studied the epidemiology of carriage among children 3-59 months old before vaccine introduction in Kilifi, Kenya. METHODS: In a rolling cross-sectional study from October 2006 to December 2008 we approached 3570 healthy children selected at random from the population register of the Kilifi Health and Demographic Surveillance System and 134 HIV-infected children registered at a specialist clinic. A single nasopharyngeal swab was transported in STGG and cultured on gentamicin blood agar. A single colony of pneumococcus was serotyped by Quellung reaction. RESULTS: Families of 2840 children in the population-based sample and 99 in the HIV-infected sample consented to participate; carriage prevalence was 65.8% (95% CI, 64.0-67.5%) and 76% (95% CI, 66-84%) in the two samples, respectively. Carriage prevalence declined progressively with age from 79% at 6-11 months to 51% at 54-59 months (p<0.0005). Carriage was positively associated with coryza (Odds ratio 2.63, 95%CI 2.12-3.25) and cough (1.55, 95%CI 1.26-1.91) and negatively associated with recent antibiotic use (0.53 95%CI 0.34-0.81). 53 different serotypes were identified and 42% of isolates were of serotypes contained in the 10-valent PCV. Common serotypes declined in prevalence with age while less common serotypes did not. CONCLUSION: Carriage prevalence in children was high, serotypes were diverse, and the majority of strains were of serotypes not represented in the 10-valent PCV. Vaccine introduction in Kenya will provide a natural test of virulence for the many circulating non-vaccine serotypes

Governance and global communities

Communities are a new form of organization in which volunteers primarily contribute to the creation of economic value. Building upon transaction cost economics, communities are investigated as a fourth form of governance structure. The concept of transaction benefits is introduced to the governance structure equation and some key variables (individual characteristics and needs, information technology, and national culture and policy) influencing transaction benefits are identified. Within communities, four major forms (restrictive, diffusive, inventive and adaptive) are identified based upon dimensions of responsiveness and transaction benefits. We conclude with a discussion of the relationship between communities and other governance structures.Governance Global communities Transaction costs Transaction benefits Open source Typology of communities

A Facile Synthesis Route of Hybrid Polyurea-Polyurethane-MWCNTs Nanocomposite Coatings for Ballistic Protection and Experimental Testing in Dynamic Regime

This study describes a simple, practical, inexpensive, improved, and efficient novel method for obtaining polyurea-polyurethane-multiwall carbon nanotubes (MWCNTs) nanocomposites with enhanced mechanical properties, and their experimental testing in a dynamic regime. SEM and micro-CT investigations validated the homogeneity of the nanocomposite films and uniform dispersion of the nanofiller inside the polymeric matrix. The experimental measurements (TGA, DSC, DMA, and tensile tests) revealed improved thermal and mechanical properties of these new materials. To demonstrate that these nanocomposites are suitable for ballistic protection, impact tests were performed on aluminum plates coated with the polyurea-polyurethane MWCNTs nanocomposites, using a Hopkinson bar set-up. The experimental testing in the dynamic regime of the polyurea- polyurethane-coated aluminum plates confirmed that the nanocomposite layers allow the metal plate to maintain its integrity at a maximum force value that is almost 200% higher than for the uncoated metallic specimens

Synthesis and characterization of polyurethane flexible foams provided from PET derivatives, fly ash, and glass wastes

The aim of this study involved the synthesis and characterization of polyurethane (PUR) foams obtained from poly(ethylene terephthalate) (PET) depolymerization products and two types of filling agents, namely fly ash and glass waste. The depolymerized PET-based products were obtained by zinc acetate-catalyzed glycolysis process in diethylene glycol (DEG) as a co-reactant. The resulting glycolysis products were contacted with methylene diphenyl diisocyanate, castor oil, and reinforcing agents. The resulting PUR specimens were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), EDX mapping, mechanical tests, and thermal analysis. The analysis confirmed that the best mechanical performances were registered by the specimens with the lowest concentration of filling agent, while the highest thermal resistance was achieved by the PUR foams with the highest concentration of reinforcing agent

Utilizing a storm-generating hotspot to study convective cloud transitions: The CACTI experiment

The Cloud, Aerosol, and Complex Terrain Interactions (CACTI) field campaign was designed to improve understanding of orographic cloud life cycles in relation to surrounding atmospheric thermodynamic, flow, and aerosol conditions. The deployment to the Sierras de Córdoba range in north-central Argentina was chosen because of very frequent cumulus congestus, deep convection initiation, and mesoscale convective organization uniquely observable from a fixed site. The C-band Scanning Atmospheric Radiation Measurement (ARM) Precipitation Radar was deployed for the first time with over 50 ARM Mobile Facility atmospheric state, surface, aerosol, radiation, cloud, and precipitation instruments between October 2018 and April 2019. An intensive observing period (IOP) coincident with the RELAMPAGO field campaign was held between 1 November and 15 December during which 22 flights were performed by the ARM Gulfstream-1 aircraft. A multitude of atmospheric processes and cloud conditions were observed over the 7-month campaign, including numerous orographic cumulus and stratocumulus events; new particle formation and growth producing high aerosol concentrations; drizzle formation in fog and shallow liquid clouds; very low aerosol conditions following wet deposition in heavy rainfall; initiation of ice in congestus clouds across a range of temperatures; extreme deep convection reaching 21-km altitudes; and organization of intense, hail-containing supercells and mesoscale convective systems. These comprehensive datasets include many of the first ever collected in this region and provide new opportunities to study orographic cloud evolution and interactions with meteorological conditions, aerosols, surface conditions, and radiation in mountainous terrain.Fil: Varble, Adam. Pacific Northwest National Laboratory; Estados Unidos. University of Utah; Estados UnidosFil: Nesbitt, Stephen William. University of Illinois at Urbana; Estados UnidosFil: Salio, Paola Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentina. Instituto Franco-Argentino sobre Estudios del Clima y sus Impactos; ArgentinaFil: Hardin, Joseph C.. Pacific Northwest National Laboratory; Estados UnidosFil: Bharadwaj, Nitin. Pacific Northwest National Laboratory; Estados Unidos. Fortem Technologies; Estados UnidosFil: Borque, Paloma. Pacific Northwest National Laboratory; Estados UnidosFil: DeMott, Paul J.. State University of Colorado - Fort Collins; Estados UnidosFil: Feng, Zhe. Pacific Northwest National Laboratory; Estados UnidosFil: Hill, Thomas C. J.. State University of Colorado - Fort Collins; Estados UnidosFil: Marquis, James N.. Pacific Northwest National Laboratory; Estados UnidosFil: Matthews, Alyssa. Pacific Northwest National Laboratory; Estados UnidosFil: Mei, Fan. Pacific Northwest National Laboratory; Estados UnidosFil: Öktem, Rusen. University of California at Berkeley; Estados Unidos. Lawrence Berkeley National Laboratory; Estados UnidosFil: Castro, Vagner. Universidade Dos Açores; PortugalFil: Goldberger, Lexie. Pacific Northwest National Laboratory; Estados UnidosFil: Hunzinger, Alexis. Pacific Northwest National Laboratory; Estados UnidosFil: Barry, Kevin R.. State University of Colorado - Fort Collins; Estados UnidosFil: Kreidenweis, Sonia M.. State University of Colorado - Fort Collins; Estados UnidosFil: McFarquhar, Greg M.. Oklahoma State University; Estados Unidos. Cooperative Institute for Mesoscale Meteorological Studies; Estados UnidosFil: McMurdie, Lynn A.. University of Washington; Estados UnidosFil: Pekour, Mikhail. Pacific Northwest National Laboratory; Estados UnidosFil: Powers, Heath. Los Alamos National High Magnetic Field Laboratory; Estados UnidosFil: Romps, David M.. University of California at Berkeley; Estados Unidos. Lawrence Berkeley National Laboratory; Estados UnidosFil: Saulo, Andrea Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentina. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; ArgentinaFil: Schmid, Beat. Pacific Northwest National Laboratory; Estados Unidos. Berkeley University; Estados UnidosFil: Tomlinson, Jason M.. Pacific Northwest National Laboratory; Estados UnidosFil: van den Heever, Susan C.. State University of Colorado - Fort Collins; Estados UnidosFil: Zelenyuk, Alla. Pacific Northwest National Laboratory; Estados UnidosFil: Zhang, Zhixiao. University of Utah; Estados UnidosFil: Zipser, Edward J.. University of Utah; Estados Unido